Hi purplelemon,
Thank you for your post, I am happy to help.
I understand that the shift key is not working on your Bluetooth keyboard. Have you ran The HP Support Assistant to aid with updates and resolving issues. Have you tried uninstalling and looking for updated driver for your keyboard?
If you connect your keyboard to a different computer does it do the same thing?
Here is a link to Notebook Keyboard Troubleshooting (Windows 8) and the HP ENVY 17t-j100 Quad Edition CTO Notebook PC Drivers for your convenience.
With Windows 8 you have a built in troubleshooter you can use.
Press the Windows key +C to open charms
Type troubleshoot Bluetooth and press enter
Follow the on screen prompts.